1. Field of the Invention
This invention is directed to a C 12-16 90% mid-cut fractionated fatty acid and a steady state manufacturing process to produce the same in commercial quantities. C 12-16-90% fatty acids may be substituted for Lauric, Myristic, C 12-14 or C 12-18 fatty acids in liquid soap products and detergents.
2. Description of the Prior Art
Fatty acids are made from naturally occurring fats and oils and comprise a mixture of different chain length hydrocarbons which are dependent on the natural distribution of the hydrocarbons in the oil feedstock. These fatty acids are referred to as whole-cut fatty acids. The resulting whole cut fatty acid is made by "splitting" the oil into fatty acid and glycerine in a hydrolyzer or kettle. The whole cut fatty acid will have the same distribution of carbon chain length molecules as the oil. As is commonly known and as exemplified in Bailey's Industrial Oil and Fat Products, Formo et at., Volume 1, Fourth Edition, pages 315 and 318, Lauric oils include the following approximate fatty acid chain length distributions:
______________________________________ Coconut Oil Palm Kernel Oil ______________________________________ C 10 and less 11-20% 6-12% C 12 44-52% 40-52% C 14 13-19% 14-18% C 16 8-12% 7-9% C 18 6-14% 13-26% ______________________________________
See also the Fatty Acid Calculator ICD, Procter & Gamble, Industrial Chemicals Division, 1985; Nutritional Data sheet for "Typical Fatty Acid Profile for Neutresca 51-25" (Refined Coconut Oil), Aarhus Inc., Sept. 1994; Fatty Acid Specifications and (Typical) Properties sheet, Procter & Gamble Chemicals 10/93; and Product Specifications including Whole Distilled Coconut Fatty Acid (C8-C18), United Coconut Chemicals, Inc. Jan. 1996. As Coconut Fatty acids are derived from plants, the chain length distribution may vary depending on where the plants were grown, the environmental conditions, i.e. drought, temperature, etc.
Fatty acids may be purified by distillation. This results in a color and odor improvement of the fatty acid distillate and a dark still bottoms cut.
Fractionation or fractional distillation is practiced to separate the whole cut fatty acid, in either distilled or undistilled form, into particular chain lengths. This is accomplished by distilling over only the desired chain length(s) based on their different boiling points. This can be done to varying degrees of purity of separation up to 99%+. The resulting fractionated fatty acid will then contain only the specific chains desired for a product application. This can have improvements in odor, color, viscosity, product performance, etc.
There are different fatty acid products which may be produced from common coconut or palm kernel oil. Some examples follow. The examples are directed to a feedstock of coconut fatty acids, however, the processes would be very similar if the feed stock were changed to palm kernel oil. The general yields are specified for both feed stocks and are typical of those percentages of an undistilled whole cut coconut oil fatty acid.
There are many different types of fatty acid products in the marketplace including C 12-18 topped distilled, pure cut fractions and mid cut fractions. The C 12-18 topped distilled acid is a technical grade fatty acid cut whereby the fractions containing 10 carbon atoms and less have been largely removed. The C 12-18 contains the C 18 chain length which was included in the whole cut fatty acid. The yield of the C 12-18 topped distilled is about 77% having an Iodine Value ("I.V.") of 5-12. At an additional expense it can be hydrogenated down to a low (&lt;l.5) I.V. for some product applications without impacting the yield.
As an alternative to the C 12-18 topped distilled cut, the C 12-18 fatty acid can be fractionated into pure cuts of specific chain lengths having a purity in the range of 90-99%. The pure cuts, however are expensive in comparison to the undistilled C 12-18 product due to the additional manufacturing steps required.
Optionally the C 12-18 bottoms cut can be fractionated into a mid cut C 12-14 product as a top cut and an undistilled C 16-18 bottoms cut. The C 12-14 mid cut fractionated fatty acid is a high quality color and odor acid with a typical I.V. of less than 0.5 and which may be used in liquid soap and detergent compositions.
During the transition from the manufacture of one product to the manufacture of another product, e.g., when switching or "lining out" from the production of C 12-99% to C 14-95%, a transitory C 12-16-90% product will be produced as a result of changing process conditions. However, the chain length distribution of this product will be skewed in that it will include only relatively small amounts of C 12's or C 16's, depending on the particular transition of products. For example, when transitioning from C 1299 to C 1416, a transitory C 12-16 product can be created with the following chain length distribution: